The Senator from Scranton

One of the most remarkable things about Barack Obama's choice of Joe Biden as his vice presidential nominee—apart from the fact that he managed to keep it secret—is that in this remarkably contentious election season, it did not seem to anger anyone. That is a remarkable feat for a party so desperate to win and for a man who has been around long enough to have made more than one generation of enemies.

Even the anger of die-hard Clinton supporters over the choice was not about Biden but about them.

With all his well-documented strengths and weakness—the elder statesman, the brawler, the survivor, the Regular Joe—Biden was the ideal choice for splitting differences; he gives everybody a little bit of what they want, most of all Barack Obama.

Tonight, Joe Biden will need to demonstrate why Obama did not make a mistake. After his speech, debate will proceed apace about what Biden brings to the ticket and whether it is what Obama hoped for. The choice may be a simpler and more pragmatic one that it seems.

Biden is passionate and hot-headed where Obama is cool and cerebral. He's a comfortingly thick-waisted and substantial 65-year-old, where Obama is suspiciously fit and skinny at 47. And of course, he is an old, white guy with a well-known story where Obama is, well, Obama.

The conventional wisdom on Biden is that he was chosen to answer charges of inexperience, particularly on foreign policy.

True. But in the end, it may just be that Joe Biden was born in Scranton, Pa., and Pennsylvania is, pun intended, a keystone in the Obama victory strategy. Biden, the Obama camp decided, is the best proxy to reach out to those white, working-class voters who flocked so decisively to Hillary Clinton in the primaries.

The audacity of the Biden pick is that Obama picked him to win a state in which he does not live. Biden represents Delaware, the second smallest state in the Union. With its three electoral votes, keeping the tiny eastern state in the Democratic column is hardly a strategic necessity. Voters will be left with the impression over the next two months that Joe Biden is the senator from Scranton. As soon as this convention is over, the Obamas and the Bidens will head directly to the Keystone State to affirm the importance of those 21 electoral votes to the Obama cause.

When the fight for the presidency goes into the homestretch after Labor Day, the race will take on a familiar cast: Republicans will be trying to hold on to Missouri, Ohio and Florida, and the Democrats will be trying to hang on to Minnesota, Michigan and Pennsylvania. Whoever can flip one of the other side's states into their column gets to advance to Pennsylvania Avenue.

Missouri and Minnesota look good for Obama. Democrats won big Senate races in both places in 2006. Obama also won both of those states in the primary fight against Hillary Clinton. Pennsylvania, on the other hand, has emerged as a problem for Obama, and he cannot win without it. Enter Sen. Biden.

Tonight, Biden will talk about his family and his long tenure in the U.S. Senate, but then he will go on and on about being born in Scranton and how Scranton still lives in him. We will hear how his wife, Jill, grew up in the Philadelphia suburbs, and how her family still lives there.

Pennsylvania has been reliably Democratic for the last four presidential cycles, but each time only narrowly so. Relying on huge turnout in solidly Democratic Philadelphia County is a tenuous strategy, at best.

In 2000, Al Gore won Pennsylvania by just over 204,000 votes but carried Philadelphia County by 348,000 votes. Four years later, Kerry ran up an even bigger margin on Bush in Philly, winning by 412,000 votes. But his margin of victory in the state shrunk to just 144,000 votes.

Obama can ill-afford to lose any of those Kerry or Gore voters to John McCain. Dreamy talk of adding Virginia or Colorado to the Democratic column, or stealing another southern state like North Carolina, is predicated on the assumption that Pennsylvania is a win.

Certainly Biden brings experience and foreign policy expertise to the Obama ticket. And he adds gray hair and gravitas to boot. But what made him the subject of that middle-of-the night text message was not his grasp of the Balkans and Middle East, but what he knows about places like Lackawanna and Luzerne counties and the rest of northeastern Pennsylvania.